Military and Civilian Airships

Airships are making a comeback, after the hindenburg syndrome held back development for decades we are now seeing modern materials and new concepts being utilized by civilian companies and the military for survailance and other applications. Could some of these craft explain some of the ufo sightings reported in recent years ? ....... i think they can. some of these images are 3d concept drawings and i have no information as to whether they are operational they are there as examples of what is being considered by modern designers. for example the aeros airship (project walrus) was cancelled by the military and was never built, the lockheed p791 however was built and tested ... i have no idea if this design was put into production though as i have not looked very deeply into this subject. **UPDATE*** lockheed's p791 is now being promoted to interested buyers the testing phase is over, see this reuters video for more info